wis·en·heim·er noun orweis·en·heim·er\ˈwīzənˌhīmə(r)\ (-s) Etymology:wise (II)+ German -enheimer (as in German family names such as Guggenheimer, Oppenheimer) : one who has the air of knowing all about something or everything : wiseacre < emerges from comparative obscurity to national prominence — much to the … chagrin of the wisenheimers — Arthur Godfrey >